Down-hole motor positioning device



July 7, 1959 w. CLARK DOWN-HOLE MOTOR POSITIONING` DEVICE Filed Sept. 1l, 1957 ATTORNEYS.

IN VEN TOR. Manci 6216K,

fill.

into the hole until the drill bit bottoms, the weight of Y the associated parts will produce a relative telescoping movement between the parts 34 and 35 which will compress the packers 38 and cause them to expand against the casing wall.

In Figure 1, there is shown a lowering tool 42. This tool may be secured to the end of a cable 43 and is provided at its lower end with a disc 42a providing an annular hook-like arrangement 42h. When it is desired to lower the assembly into the well casing, the body with the downhole motor and bit attached thereto is suspended from the tool 42 by engagement of the hook elements 30 of the fingers 12 over the annular hook element 42b of the tool 42. It will be understood that the fingers 12 must be pivoted inwardly manually and that thereby through action of the notches 26 of the fingers 12 against the shoulder 25, the spring 20 is compressed. By this action also the shoulder 27 is moved downward slightly so that the fingers may assume the position of Figure l. The weight of the assembly suspended from the tool 42 maintains the parts in the position of Figure l.

As the assembly is being lowered down the hole through the well casing, the well casing serves to hold the fingers 15 in position where the notches 27 assist in maintaining the spring under compression.

At the bottom of the hole at the end of the casing string there is provided a special casing section indicated generally at 44 in Figure 2. This special casing section is provided with axial slots 45 to accommodate the fingers 12 and a joining section 46 is threaded into the upper end of the section 44 to provide the annular shoulder 47. The section 46 is threaded at 48 so that it Y may be screwed into the next upper casing section. The special section 44 is also provided with the recess 49 for the reception of the fingers 15. The casing section v 44a is screwed into the lower end of the section 44, and the upper end of the section 44a is configured as shown in Figure 7 to provide the angular surfaces or teeth 44b. When the section 44a is screwed into the section 44, the members 44b lie within the section 44 in the recess 49. As the fingers 15 engage the members 44b with their beveled edges 15a, the positioning device is rotated and oriented so that the fingers 12 may enter their slots 45. Eight slots 45 have been shown, and eight members 44b; however there are only four fingers 12 and four fingers 15. The number of fingers and slots may of course be varied if desired. The member 44a provides the lower shoulders 50 against which the lower ends of the fingers 15 may abut. The special section 44a is also slotted as at 51 for the passage of fluid through the member 34 and down into the hydraulic motor. The hydraulic motor indicated generally at 41 is screwed into the lower end of the positioning structure by means of the threads 40. It will not be described in detail since it is fully disclosed and claimed in an application of Wallace Clark, Serial No. 582,016 filed May l, i956, and also in a copending application filed October 30. 1957, now abandoned, bearing Serial No. 693,319, in the names of Wallace Clark and Harry Conrad. I have also shown an additional casing section 52 screwed onto the bottom of the section 44a and having the internal cam surface 53 to assist in collapsing the collapsible bit indicated generally at 54. The collapsible bit is the one described in my copending application, Serial No. 683,391, mentioned above.

When the assembly comprising the positioning tool of Figure l with the motor and bit attached thereto and suspended from the lowering tool 42 as shown is lowered into the hole through the well casing, nothing obstructs its movement until the fingers 15 enter the annular space 49. The fingers 15 which are under some slight pressure from the spring 20, enter the recess 49 and upon contact with the members 44b they rotate the device to orient the fingers 12 with the slots 4-5, and then the shoulders 50 prevent further downward movement of the assembly. As soon as tension is removed from the cable 43, the spring 20 forces the plunger 18, 21, 23, upwardly to firmly thrust the fingers 15 outwardly and also to thrust the fingers 12 outwardly. These fingers then enter the slots 45 and the shoulders provided by the hook elements 28 thereof abut against the shoulder 47 of the member 46. This abutment locks the device against upward thrust and the entry of the fingers into the slots 45 locks the device against rotation. It will be noted that when the fingers 12 move outwardly, the lowering tool 42 becomes freed and can be lifted out of the hole. Fluid can then be pumped down the well casing, as diagrammatically indicated, to drive the downhole motor and operate the bit.

When it is desired to lift the assembly out of the hole, a lifting tool is employed as shown in Figure 4. The lifting tool comprises a member 55 hollow as indicated at 56 and having the inwardly directed annular hook element 57. The internal walls of the hollow 56 are sloped as indicated at 58. The member 55 may be attached to a cable and when it is lowered into the hole the chamfered inner surface 59 of the lifting tool cooperates with the cam surfaces 29 of the ngers 12 to force the fingers 12 inwardly until the hook element 57 engages in the hook elements 28 heretofore described. This action, through the notches 26 and the shoulder 25, forces the member 23 downwardly compressing the spring 20 and removing the thrust from the fingers 15. The fingers 15 in their locked position are in the position shown in Figure 2 wherein their surfaces 32 lie substantially flush in the annular recesses 49. The surfaces 31 thus constitute cam surfaces so that as the assembly is raised, the fingers 51 will be forced inwardly, thus further compressing the spring 20 and permitting the fingers 15 to pass through the casing.

From the foregoing description, it will be seen that I have provided a device by means of which a down-hole motor can be positioned against upward, downward and rotational movement with respect to a special casing section at the bottom of a Well and that I have provided simple means for lowering the device to its operative position and for lifting it out of its operative position.

It will be understood that various modifications may be made without departing from the spirit of my invention and I therefore do not intend to limit myself except as set forth in the claims which follow.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A structure for positioning a down-hole motor and drill in a well casing at the bottom of a hole, comprising a body of dimensions to pass through said casing, means on said body for the attachment of a motor to the lower end thereof, a set of upwardly extending fingers symmetrically disposed about said body and pivoted thereto at their lower ends, a set of downwardly extending fingers symmetrically disposed about said body below said upwardly extending fingers and pivoted to said body at their upper ends, a plunger axially slidably mounted in said body, spring means urging said plunger upwardly, said plunger having means abutting said upwardly extending fingers to urge them to swing outwardly, and also having means abutting said downwardly extending fingers to urge them to swing outwardly; and means at the upper ends of said upwardly extending fingers for alternatively attaching a lowering tool or a raising tool.

2. A structure according to claim 1, wherein said means for alternatively attaching'a lowering tool or a raising tool comprises, at the upper ends of said upwardly extending fingers, inwardly directed hook elements and outwardly directed hook elements, the upper ends of said upwardly extending fingers having cam surfaces leading outwardly toward said outwardly directed hook elements.

3. A structure according to claim 2 in combination with a lowering tool, said tool being attachable to a cable and having an annular outwardly directed hook member, said body being suspendable from said tool by the engagement of the inwardly directed hook elements of said fingers with said annular hook member, against the action of said spring means, and being disengageable by a slight lowering of said tool when said body is positioned in said casing.

4. A structure according to claim 2, in combination with a lifting tool, said tool being attachable to a cable and being generally bell-shaped and terminating in an annular inwardly directed hook element, said tool being engageable with said body by being lowered over said fingers, said inwardly directed hook element riding over said cam surfaces, causing said ngers to pivot inwardly until said last named hook element engages the outwardly directed hook elements on said fingers.

5. A structure according to claim 1, in combination with a casing section adapted to be installed at the lower end of a string of casing and having slots t'o receive said upwardly extending fingers, and orienting means arranged to coact with said downwardly extending iingers to rotate said body to insure the entry of said upwardly extending ngers into said slots.

6. A structure for positioning a down-hole motor and drill in a well casing at the bottom of a hole, comprising a body of dimensions to pass through said casing, means on said body for the attachment of a motor to the lower end thereof, a set of upwardly extending lingers symmetrically disposed about said body and pivoted thereto at their lower ends, a set of downwardly extending ngers symmetrically disposed about said body below said upwardly extending fingers and pivoted to said body at their upper ends, a plunger axially slidably mounted in said body, spring means urging said plunger upwardly, said plunger having means abutting said upwardly extending fingers to urge them to swing outwardly, and also having means abutting said downwardly extending lingers to urge them to swing outwardly; in combination with a casing section adapted to be installed at the lower end of a string of casing, said section having an annular recess providing a lower shoulder into which recess and against which shoulder said downwardly extending lingers may extend to lock said structure against downward movement, said section also having vertical slots symmetrically disposed thereabout and in number equal to said upwardly extending lingers and providing upper shoulders, into which slots and against which shoulders said upwardly extending lingers may extend to lock said structure against upward and rotational movement; and means at the upper ends of said upwardly extending ngers for alternatively attaching a lowering or a lifting tool.

7. A combination according to claim 6, wherein orienting means are provided in said annular recess and arranged to coact with said downwardly extending fingers to rotate said body to insure the entry of said upwardly extending fingers into said slots.

References Cited in the tile of this patent UNITED STATES PATENTS 

